My 2014 MacBook air 2014 forgets Wi-Fi passwords. When I enter a Wi-Fi password and I reboot or let it go to sleep, then I have to retype the password again. I am running macOS Mojave, so I can't keychain first-aid. It gives an error. I tried reset keychain didn't work made it worse That's all I did.
I tried some things to fix it. Reset the keychain didn't work, deleting the keychain and rebooting didn't work forget and retype all passwords via wifi settings didn't work